Abstract
This study investigated the ozone formation mechanism and air mass trajectory via simultaneous air quality sampling around the coastal region of urban Kaohsiung. Vertical concentration profiles of O3 and its precursors (NO(subscript x) and VOCs) were sampled and measured at inland and offshore sites during eight intensive sampling periods. The intensive sampling periods were divided into three categories based on meteorological condition: the sea-land breeze period, the northeastern monsoon period, and the mixed period. Vertical profile results showed that the stratification of O3 was commonly observed at 40 out of 64 sampling sites accounting for 62.5% of the total O3 measurement. The results obtained from VOCs measurement indicated that the major species of VOCs was acetone, which accounted for 16.25-64.05% of total TVOCs- C2 in the offshore region, while the major species of VOCs in the inland region was toluene, which accounted for 6.41- 43.77 % of total TVOCs-C2. Backward trajectories showed that air pollutants emitted from land sources could transport to the offshore region, resulting in a high concentration of oversea NO(subscript x) and VOCs. Major species of VOCs with high O3 formation potential were found to be aromatics in the low atmosphere around the coastal region of metro Kaohsiung.
Highlights
Kaohsiung-Pindong air quality zone (KP air quality zone), covering Kaohsiung City and Pindong County, has been officially labeled by Taiwan's Environmental Protection Administration (TEPA) as the worst air quality region (6– 8% of poor air quality with PSI > 100) among seven Air Quality Zones (AQZ) in Taiwan (Tsai et al, 2010)
Meteorological Measurement Data Taiwan is geologically located in the East Asian subtropical zone, and is significantly influenced by the northeastern monsoon (NEM) blown from late fall to late spring and by the southwestern monsoon blown from summer to mid-fall
This study investigated ozone formation mechanisms and air mass trajectories via simultaneous air quality sampling over the coastal region of metro Kaohsiung
Summary
Kaohsiung-Pindong air quality zone (KP air quality zone), covering Kaohsiung City and Pindong County, has been officially labeled by Taiwan's Environmental Protection Administration (TEPA) as the worst air quality region (6– 8% of poor air quality with PSI > 100) among seven Air Quality Zones (AQZ) in Taiwan (Tsai et al, 2010). Major ambient air pollutants in metro Kaohsiung are mostly higher than that those at other AQZs in Taiwan (Tsai et al, 2008). High O3 concentration is a major environmental concern due to its adverse impacts on human health and its key role in the photochemical reaction cycles affecting the formation and fate of its precursors (NOx and VOCs). There is a non-linear relationship between the concentrations of these two species and the formation concentration of O3 (Na et al, 2005), and the ratios of [TVOCs-C2]/[NOx] in the offshore regions near Kaohsiung are high, indicating that O3 formation in these regions is NOx-limited. The ratios of [TVOCs-C2]/[NOx] in the inland regions are relatively lower, the ratio of some cases were even below 4, showing that O3 formation is VOCs-limited.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
